Inerters represent two-terminal devices in mechanical networks in which forces applied at the two terminals are equal, opposite, and proportional to a relative acceleration between the terminals. In the study of mechanical networks, the inerter can represent as the mechanical equivalent of a capacitor of an electrical network. Inerters have been used to control forces of a linear input relative to a fixed second terminal. Such linear inerters have incorporated rack-and-pinion, ball screw, and hydraulic designs.